/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.uima.util;
import java.io.IOException;
import java.io.InputStream;
import org.apache.uima.cas.CAS;
import org.apache.uima.cas.impl.OutOfTypeSystemData;
import org.apache.uima.cas.impl.XCASDeserializer;
import org.apache.uima.cas.impl.XmiCasDeserializer;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.XMLReaderFactory;
/**
* Deserializes a CAS from a standoff-XML format. This class can read the XMI format introduced in
* UIMA v1.4 as well as the XCAS format from previous versions.
*/
public abstract class XmlCasDeserializer {
/**
* Deserializes a CAS from a standoff-XML format.
*
* @param aStream
* input stream from which to read the XML document
* @param aCAS
* CAS into which to deserialize. This CAS must be set up with a type system that is
* compatible with that in the XML.
*
* @throws SAXException
* if an XML Parsing error occurs
* @throws IOException
* if an I/O failure occurs
*/
public static void deserialize(InputStream aStream, CAS aCAS) throws SAXException, IOException {
deserialize(aStream, aCAS, false);
}
/**
* Deserializes a CAS from XMI.
*
* @param aStream
* input stream from which to read the XML document
* @param aCAS
* CAS into which to deserialize. This CAS must be set up with a type system that is
* compatible with that in the XML
* @param aLenient
* if true, unknown Types will be ignored. If false, unknown Types will cause an
* exception. The default is false.
*
* @throws SAXException
* if an XML Parsing error occurs
* @throws IOException
* if an I/O failure occurs
*/
public static void deserialize(InputStream aStream, CAS aCAS, boolean aLenient)
throws SAXException, IOException {
XMLReader xmlReader = XMLReaderFactory.createXMLReader();
ContentHandler handler = new XmlCasDeserializerHandler(aCAS, aLenient);
xmlReader.setContentHandler(handler);
xmlReader.parse(new InputSource(aStream));
}
static class XmlCasDeserializerHandler extends DefaultHandler {
private CAS mCAS;
private boolean mLenient;
private ContentHandler mDelegateHandler; // will be set to either XMI or XCAS
XmlCasDeserializerHandler(CAS cas, boolean lenient) {
mCAS = cas;
mLenient = lenient;
}
public void startElement(String uri, String localName, String qName, Attributes attributes)
throws SAXException {
if (mDelegateHandler == null) {
// try to find out whether we should use the XCAS or XMI deserializers
// if there's an xmi:version attribute, always use XMI
String xmiVer = attributes.getValue("xmi:version");
if (xmiVer != null && xmiVer.length() > 0) {
XmiCasDeserializer deser = new XmiCasDeserializer(mCAS.getTypeSystem());
mDelegateHandler = deser.getXmiCasHandler(mCAS, mLenient);
} else if ("CAS".equals(localName)) // use XCAS
{
XCASDeserializer deser = new XCASDeserializer(mCAS.getTypeSystem());
mDelegateHandler = deser
.getXCASHandler(mCAS, mLenient ? new OutOfTypeSystemData() : null);
} else // default to XMI
{
XmiCasDeserializer deser = new XmiCasDeserializer(mCAS.getTypeSystem());
mDelegateHandler = deser.getXmiCasHandler(mCAS, mLenient);
}
mDelegateHandler.startDocument();
}
mDelegateHandler.startElement(uri, localName, qName, attributes);
}
public void characters(char[] ch, int start, int length) throws SAXException {
mDelegateHandler.characters(ch, start, length);
}
public void endDocument() throws SAXException {
mDelegateHandler.endDocument();
}
public void endElement(String uri, String localName, String qName) throws SAXException {
mDelegateHandler.endElement(uri, localName, qName);
}
public void error(SAXParseException e) throws SAXException {
throw e;
}
public void fatalError(SAXParseException e) throws SAXException {
throw e;
}
public void warning(SAXParseException e) throws SAXException {
throw e;
}
}
}